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Fig. 9-13. Pasture mealybug, Balanococcus poae (photos: AgResearch).


Mealybugs (several species and genera) are not readily observed pests in pasture and turf because of their small size and location in among leaf sheaths or underground where they often are concealed in a white waxy substance resembling cottonwool. Mealybugs feeding on the plant sap will debilitate their hosts, causing plant discoloration and death, but damage symptoms may become obvious only during a drought. An endemic species in New Zealand, the pasture mealybug [Balanococcus poae (Maskell)] (Fig. 9-13), has severely damaged tall fescue and ryegrass pastures within 2 yr of sowing (Pennell and Ball, 1999). This species is found feeding on the crown and upper roots of the host, causing visible damage in autumn and early winter. A similar species, the rhodesgrass mealybug [Antonina graminis (Maskell)] is found throughout the United States and also can damage tall fescue.

Effect of Endophyte

The presence of endophyte dramatically reduced infestation of grasses by pasture mealybugs. In a grazing trial in New Zealand, up to 91% of E- tall fescue plants were infested with pasture mealybug 2 yr after sowing compared with between 2 and 11% of the E+ plants (Pennell and Ball, 1999). Several Neotyphodium endophytes were tested in this trial, including some that do not produce ergopeptine alkaloids. Compared with E- tall fescue, E+ plants have been reported to harbor fewer Phenococcus solani (Ferris), a polyphagous species of mealybug that feeds on the tillers (Sabzalian et al., 2004).


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